Marin IJ Articles

Gardening myths are as common as blackbirds in a sunflower field. Some have just become bad habits; others have been passed down for generations. While it may be tempting to believe that everything your grandma taught you about gardening was true, there may be a few little tidbits you can do without. Here are ten gardening myths debunked.

Lawns are low maintenance. Lawns are, quite simply, maintenance hogs. To keep a lawn looking good, you must water (a lot), mow, fertilize, edge, aerate, and weed. And that's just the ongoing maintenance. You will also need to trap the occasional underground varmint, repair sprinkler heads, and seed or patch bare spots. That sound you hear? It's the shrubs in your garden laughing at all the time you spend babying that water-guzzling grass.

If in doubt, fertilize. Those bags of chemicals sitting on the shelves at your favorite nursery are tempting. If your garden is looking ragged, would a few handfuls perk things up? This is often the first go-to for nursery professionals who do not have the benefit of seeing your garden (or your gardening techniques) first hand. More often than not, tossing fertilizer on a struggling garden will have little effect, and the excess will be swept away in the next rainstorm where it will end up polluting our beloved bay. Most plants can get everything they need from soil that has been amended with compost and topped with mulch.

There's nothing you can do about your clay soil. If you have clay soil you have two choices. You can 1) select plants that like clay soil (yes, they do exist) or 2) you can amend your soil by adding significant quantities of organic material such as compost. This second option requires that you spread an inch or two of compost, topped with mulch, every year. If you aren't into schlepping loads of compost into your garden, you can always plant a cover crop such as vetch or fava beans, and then chop it up and turn it under. Any way you slice it, amending soil takes work. Do not succumb to the related myth about adding sand to amend clay soil, because you will end up with something resembling cement.

The best irrigation strategy is "set it and forget it." If you've installed a drip system, good for you. It's a positive step in minimizing water use. But drip systems require maintenance. Before you turn on your system each year, check for leaks and other problems such as missing or clogged emitters. Dial back your run times for established plants. Remember, the goal is to water as little as possible.

You can have a NO maintenance garden. Nice try. Even gravel needs an occasional dusting off, and weeds do sprout in the cracks of asphalt. The lowest maintenance gardens include plants that do not require supplemental water or pruning once established. If you want a low maintenance garden, be sure your soil is in tip-top shape and select plants wisely. A good place to start is the Water Wise Plant Guide on the Marin Master Gardener website.

Planting invasive plants is no big deal. They sell ivy and broom at some nurseries, so it must be okay to plant them, right? Wrong. Invasive plants take a toll in numerous ways. They overrun native species and reduce the number of pollinators, ultimately altering the food web. They proliferate so quickly and densely that they can increase the risk of fire. Native species help keep soil and waterways healthy, while invasive species do not. Invasive species are also expensive, costing billions of dollars every year to eradicate. Invasive species also change the look and feel of our natural environment. Don't believe me? Take a walk up on King Mountain in Larkspur, which is completely overrun with broom.

Organic pesticides are always safer than synthetic pesticides. "Natural" does not always mean better or safer. Take nicotine sulfate, for instance, an insecticide that is derived from tobacco. This organic product is extremely toxic to humans and other animals if it is absorbed through the skin. Another common insecticide, rotenone, is derived from the roots of tropical bean plants. This sounds innocuous, but it is considerably more toxic than its synthetic equivalent. Nicotine and rotenone break down rapidly, which means the biggest hazard is to the people and wildlife present at the time of application. Always start with the least toxic control option available, and read product labels and precautions closely.

Watering in the middle of the day will burn leaves. This one is a head scratcher. If rain somehow caused leaves to burn, those millions of acres of farmland that stretch across the greater United States would be prime targets. But rain—or water from a sprinkler—does not cause leaves to burn. It's true that some plants do not like to have wet foliage, but it's easy to sidestep that issue by watering with drip irrigation.

Drought tolerant plants never need water. Almost all plants need to be watered heavily when they're first planted. This is why fall and winter are a great time to plant, because Mother Nature can do the initial watering for you. Once plants are established, it's important to know their water requirements. Some plants can truly survive on zero supplemental water, while others will need regular irrigation.

Your local nursery is your best source of gardening information.Your nurseryman may be extremely knowledgeable, but he also wants to sell you what's in his store. It pays to educate yourself so that you are not at the mercy of whatever he happens to have in stock. The Master Gardeners are an excellent source of information. Come visit us at the Farmers Market or check out our numerous educational events that are listed on the website.